The Effect of HMG-CoA Reductase Inhibitors
(Statins) on Bone Mineral Density
Holly Funkhouser
Objectives: It has been shown that 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, statins, reduce blood cholesterol and the risk for cardiovascular disease. Recent studies have suggested that the use of statins can increase bone mineral density, BMD. Osteoporosis can be defined as a low bone mineral density. Osteoporosis threatens 100 million people worldwide. HMG-CoA reductase inhibitors could work by decreasing bone resorption or by increasing bone formation. Either way it would be a good treatment for osteoporosis. There have not been many studies on the affect of HMG-CoA reductase inhibitors on BMD. It has been shown in animal studies that the use of statins in mice increased bone formation. Two studies in the June 28, 2000 issue of JAMA showed that there was a decrease in hip fractures and other bone fractures in elderly patients that were currently using statins. I hypothesize that there will be a higher BMD in patients that are currently using statins, once all confounders are accounted for.
Methods: Approximately 1151 patients had bone mineral density measurements on file ending December 31,2000. The scores from these bone mineral densities were retrieved as well as medication, height, weight, race and age. From this data BMI and length of time on medication will be calculated. The patients will be divided up onto those that have been on or are currently on an HMG-CoA reductase inhibitors and those that are not. T-tests will be performed to determine if there is a statistical difference between the control and case patients. The final number of patients entered into the study was 983, with 197 in the exposed group and 786 in the non-exposed group. Cox regression models will be developed to account for confounders.
Results: A total of 786 never received any statin drug prior to their bone mineral density. A total of 197 received statin at least one time with 139 of them receiving the drug for greater than 12 months. The largest percentage of our population was men (70%), due to the location of the research. Our group was also largely white (71%) and over the age of 60 (60%). Once gain this was due to the location of the research. The overall spine BMD, total hip BMD and Neck BMD were all higher in the statin use group. As expected, the statin use group had a lower percentage of subjects that had diagnosed osteoporosis (24% vs. 30%, respectively).
Conclusion: It appears that statins due increase bone mineral density. This could be a great advancement in the treatment of osteoporosis. However, one must still be careful I prescribing statins as treatment for osteoporosis until the findings can be proved with a double blind randomized placebo controlled trial.
